Add columns from file to an existing table in MariaDB 10.1 - mariadb

Question

I want to add a new column from a file to an existing table, in the way cbind does in R.
The file has 1 column, 23710 lines, all numbers:
me#my_server:/var/www/html/my_website$ head my_sample.txt
61
66
0
330
76
9
10
16
6
0
Using the code:
ALTER TABLE my_table ADD COLUMN IF NOT EXISTS sample69 INT(10) DEFAULT NULL;
LOAD DATA LOCAL INFILE '/var/www/html/my_website/my_sample.txt' INTO TABLE my_table LINES TERMINATED BY '\n' (sample69);
Before:
MariaDB [my_database]> select * from my_table limit 10;
+------------+-----------+
| geneSymbol | sample000 |
+------------+-----------+
| A1BG | 61 |
| A1BG-AS1 | 66 |
| A1CF | 0 |
| A2M | 330 |
| A2M-AS1 | 76 |
| A2ML1 | 9 |
| A2MP1 | 10 |
| A4GALT | 16 |
| A4GNT | 6 |
| AA06 | 0 |
+------------+-----------+
MariaDB [my_database]> select count(*) from my_table;
+----------+
| count(*) |
+----------+
| 23710 |
+----------+
After:
MariaDB [my_database]> select * from my_table limit 10;
+------------+-----------+-----------+
| geneSymbol | sample000 | sample69 |
+------------+-----------+-----------+
| A1BG | 61 | NULL |
| A1BG-AS1 | 66 | NULL |
| A1CF | 0 | NULL |
| A2M | 330 | NULL |
| A2M-AS1 | 76 | NULL |
| A2ML1 | 9 | NULL |
| A2MP1 | 10 | NULL |
| A4GALT | 16 | NULL |
| A4GNT | 6 | NULL |
| AA06 | 0 | NULL |
+------------+-----------+-----------+
MariaDB [my_database]> select count(*) from my_table;
+----------+
| count(*) |
+----------+
| 47420 |
+----------+
It apparently appends the data to the end of the column. Instead I want the new column to be the same length of 23710, filled with the new data from the file.
What am I doing wrong?

Answer 1

LOAD only loads whole rows.
Even if it could load just one column, how would it know which row each number goes with?
You must reconstruct the data with two columns (geneSymbol and sample69), load that into a temp table, then do a multi-table JOIN to move the data into the main table.
Addenda
If you have 69 columns of samples, that it the wrong way to design the schema. At some point, you will hit a limit.
Plan A: Lots of rows, not lots of columns:
CREATE TABLE x (
geneSymbol VARCHAR(..) ...,
num SMALLINT UNSIGNED NOT NULL,
value SMALLINT UNSIGNED NOT NULL,
PRIMARY KEY(geneSymbol, num)
) ENGINE=InnoDB
Plan B (This will require code to add each new sample):
CREATE TABLE x (
geneSymbol VARCHAR(..) ...,
text NOT NULL, -- JSON encoded list of samples for that gene
PRIMARY KEY(geneSymbol)
) ENGINE=InnoDB
Plan C (aimed at reading one sample):
CREATE TABLE x (
num SMALLINT UNSIGNED NOT NULL,
text NOT NULL, -- JSON encoded list of values for that sample
PRIMARY KEY(num)
) ENGINE=InnoDB
What will your queries be like? I suspect you will be reading all the data, not doing any WHERE clauses based on symbol or num??